Such a device generally comprises a floor arranged such that it receives particles of a specific shape and broken fragments of such particles, connected to a first means arranged such that it makes the floor undergo a vibratory movement such that the particles and broken fragments in question move on the floor in a direction determined by the type of vibratory movement it is made to undergo, the floor being pierced with orifices of a shape predetermined as a function of the shape of the particles, in order to allow the broken fragments of such particles to pass through the orifices without allowing the particles themselves to pass therethrough.
For example, the two dimensions (length, width) of such an orifice can be slightly greater than two of the three dimensions (length, width, height) of a particle, however less than the third dimension thereof. Therefore, a broken particle fragment, the third dimension of which is reduced relative to that of a whole particle, can easily fall into the orifice in question, whereas a whole particle could only fall therethrough by being tilted along an axis of symmetry that is orthogonal to the third dimension. In such a case, the fraction of whole particles that has nonetheless passed through the floor of the device by way of some of the orifices thereof can be recovered upstream using appropriate means. Such a device generally further comprises a ceiling arranged substantially parallel to the floor of the device.
Document FR2841161, for example, discloses such a device.
One problem caused by such devices is that the broken fragments, the third dimension of which is greater than or equal to at least one of the two dimensions of the orifices of the floor of the device can become stuck in the orifices and thus block same. In such a situation, as the process for separating the broken fragments from the whole particles by the device progresses, an increasing number of orifices can become blocked in this manner, which reduces the separating efficiency of the device to an equal degree.
In such a situation, the operation of the device is usually stopped in order to manually, or by way of mechanical means, unblock the orifices in which the broken particle fragments have become stuck. This operation therefore results in a loss of time and therefore of productivity and an additional workforce is required to perform the operation.